Refinements of Hermite-Hadamard inequality for operator convex function

In this paper, we present several operator versions of the Hermite-Hadamard inequality for the operator convex function, which are refinements of some operator convex inequalities presented by Dragomir [S. S. Dragomir, Appl. Math. Comput., 218 (2011), 766–772] and [S. S. Dragomir, RGMIA Research Report Collection, 2016 (2016), 15 pages].